The individual crystals in phaneritic texture are readily visible to the unaided eye. C) The extrusive magma cools quickly so the mineral grains do not have time to grow. C) the magma comes in contact with water and freezes. MAGMA - molten material and dissolved gas (in the subsurface). When porphyritic, it often has either olivine or plagioclase phenocrysts. What does it mean if a rock has a coarse texture? D. quartz For information on user permissions, please read our Terms of Service. A. 2. When volcanoes erupt explosively, vast amounts of lava, rock, ash, and gases are thrown into the atmosphere. B. volume is very large, comparable in size with granitic batholiths B) Andesite C. potassium feldspar C. Al and Si are the least abundant elements in the magma. This process transfers heat and creates magma. Diorite is identifiable by its Dalmatian-like appearance of black hornblende and biotite and white plagioclase feldspar. This more gaseous and sticky lava tends to explode violently and cools as andesite rock. It is commonly grey and porphyritic. 1. Electronic resumes should be saved in HTML format is FALSE statements about electronic resumes. Composition refers to the rocks specific mineralogy and chemical composition. Obsidian as a glassy rock shows an excellent example of conchoidal fracture similar to the mineral quartz (see Chapter 3). As the denser tectonic plate subducts, or sinks below, or the less-dense tectonic plate, hot rock from below can intrude into the cooler plate above. When located beneath the ocean, these plumes, also known as hot spots, push magma onto the seafloor. C) light colored, less dense and more viscous (sticky); 1. granite Magma forms under Earth's surface at about 800 to 1300C in the crust or mantle and erupts on Earth's surface as lava.When magma or lava cools, it solidifies by crystallization in which minerals grow within the magma or lava. If a magma chamber encounters an enormous amount of pressure, however, it may fracture the rock around it. 1. diorite and gabbro The solid parts, called tephra, settle back to earth and cool into rocks with pyroclastic textures. The fine-grained texture indicates the quickly cooling lava did not have time to grow large crystals. Examples of rhyolite include several lava flows in Yellowstone National Park and the altered rhyolite that makes up the Grand Canyon of the Yellowstone. Intrusive rocks, forming underground with larger, stronger crystals, are more likely to last. Typical intermediate rocks are diorite and andesite. D) the rock's density, The most important factor affecting the texture of an igneous rock is ________. Decompression melting also occurs at mantle plumes, columns of hot rock that rise from Earths high-pressure core to its lower-pressure crust. if((replacementValue > 0) && (replacementValue < limit)). 3. phaneritic Because the earth was largely molten at its origin, magma may be considered the beginning of the rock cycle. Batholiths and stocks are discordant intrusions that cut across and through surrounding country rock. 5. gabbro If any melting takes place, crystal settling will make the magma at the bottom of the chamber more mafic than it was to begin with (Figure 3.3.6c). Condie) 11, 1144 (Elsevier, 1994). Magma is molten rock below Earths surface. St. Helens volcano, and why? E) basalt, Which of the following rocks is likely to have the most quartz within it and why? This heat makes magma a very fluid and dynamic substance, able to create new landforms and engage physical and chemical transformations in a variety of different environments. Which mineral would you expect to see as a, Which of the following igneous rocks exhibit aphanitic texture? At that temperature, the plagioclase is calcium-rich (anorthite) (see Figure 2.6.1). This relates to the cooling history of the molten magma from which it came. Diorite is a coarse-crystalline intermediate intrusive igneous rock. B. may be composed of grains of olivine and pyroxene phenocrysts B) the first crystals to form when the magma was in the magma chamber B) The glass is formed mostly when magma cools deep beneath the surface whereas phaneritic rocks cool at the surface. 1. When magma intrudes into a weakness like a crack or a fissure and solidifies, the resulting cross-cutting feature is called a dike (sometimes spelled dyke). Low viscosity means that mafic magma is the most fluid of magma types. The Journal of Geology 39, 5467 (1931). The purpose of writing a rsum is to get a job. Felsic magmas, on the other hand, have much more SiO2 (65% to 75%) and Na2O + K2O (around 10%) and much less FeO and MgO plus CaO (about 5%). E) Both a. and c. D) considered "volcanic" rocks because they form from lava extruded at the surface; considered "plutonic" rocks because they form from magma beneath the surface. Working mostly with basaltic magmas, he determined the order of crystallization of minerals as the temperature drops. Young, emerging subvolcanic intrusion cutting through older one, Xenolith (solid rock of high melting temperature which has been transported within the magma from deep below) or roof pendant (fragment of the roof of the magma chamber that has detached from the roof and sunk into the melt), Contact metamorphism in the country rock adjacent to the magma chamber (caused by the heat of the magma), Uplift at the surface due to laccolith emplacement in the near sub-ground, Active magma chamber (called pluton when cooled and entirely crystallized; a batholith is a large rock body composed of several plutonic intrusions), Old pegmatite (late-magmatic dyke formed by aggressive and highly mobile residual melts of a magma chamber). Please select the best answer from the choices provided To give an example of how large these crystals can get, transparent cleavage sheets of pegmatitic muscovite mica were used as windows during the Middle Ages. If you have questions about licensing content on this page, please contact ngimagecollection@natgeo.com for more information and to obtain a license. Diorite is a coarse-crystalline intermediate intrusive igneous rock. The pool of magma in a magma chamber is layered. Gabbro is a coarse-grained mafic igneous rock, made with mainly mafic minerals like pyroxene and only minor plagioclase. C) basaltic, rhyolitic Residual molten material expelled from igneous intrusions may form veins or masses containing very large crystals of minerals like feldspar, quartz, beryl, tourmaline, and mica. A stock is a type of pluton with less surface exposure than a batholith and may represent a narrower neck of material emerging from the top of a batholith. Regardless, when a diapir cools, it forms a mass of intrusive rock called a pluton. F) basalt; extrusive rock that formed from cooling of relatively low silica lava, Match the volcano with the appropriate rock formed by its eruption. Some igneous rocks have a mix of coarse-grained minerals surrounded by a matrix of fine-grained material in a texture called porphyritic. Haydn's opus 33 string quartets were first performed for This non-crystalline material is not classified as minerals but as volcanic glass. In a porphyritic volcanic rock, which mineral grains are the last to crystallize? Tapping into Magmas PotentialIn 2009, the Icelandic Deep Drilling Project created a well that uses magma to generate geothermal energy. B. higher values of this require greater temperatures for melting In some cases, however, partially cooled but still liquid magma, with crystals in it, will either move farther up into a cooler part of the crust, or all the way to the surface during a volcanic eruption. Rocks labeled as granite in laymen applications can be several other rocks, including syenite, tonalite, and monzonite. a. Extrusive igneous rocks have a fine-grained or aphanitic texture, in which the grains are too small to see with the unaided eye. The process by which the same magma may produce different composition igneous rocks. These tiny crystals can be viewed under a petrographic microscope [1]. D) phaneritic, __________ is named for a prominent, volcanic mountain range in western South The Rights Holder for media is the person or group credited. Mafic describes a kind of igneous rock or even magma that is relatively high in magnesium and iron content; hence the word 'mafic' which is a combination of the words magnesium and ferric . D) gabbroic, granitic, The classification of igneous rocks is based on __________. Plus, they are, by definition, exposed to the elements of erosion immediately. D. Heavier crystals float on the top of the magma in the magma chamber producing a layered igneous rock upon complete solidification. The fine-grained texture indicates the quickly cooling lava did not have time to grow large crystals. B) The rock has mineral grains that are glassy. Tephra fragments are named based on sizeash (<2 mm), lapilli (2-64 mm), and bombs or blocks (>64 mm). When magma is ejected by a volcano or other vent, the material is called lava. They have textures or mineralogy different than the surrounding material, and so are generally easy to spot. D. occurs when confining pressure drops significantly, like under the ocean ridges The slow cooling process allows crystals to grow large, giving the intrusive igneous rock a coarse-grained or phaneritic texture. = 2 1/4. 2. porphyritic andesite Magma originates in the lower part of the Earths crust and in the upper portion of the mantle. Granite is a course-crystalline felsic intrusive rock. B) basaltic - very sticky magma makes for very passive (fluid) eruptions The resulting rock is called volcanic glass. 1. aphanitic B) Intrusive magma flows onto the Earth's surface and cools very slowly, allowing many small mineral grains to grow. Rocks that solidify from lava flows are typically finer grained than those that crystallize intrusively. 6 2/3 B) basalt Book: An Introduction to Geology (Johnson, Affolter, Inkenbrandt, and Mosher), { "5.01:_Classification_of_Igneous_Rocks" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "5.02:_Bowens_Reaction_Series" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "5.03:_Magma_Generation" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "5.04:_Partial_Melting_and_Crystallization" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "5.05:_Volcanism" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()" }, { "00:_Front_Matter" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "01:_Understanding_Science" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "02:_Plate_Tectonics" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "03:_Crustal_Deformation_and_Earthquakes" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "04:_Minerals" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "05:_Igneous_Processes_and_Volcanoes" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "06:_Metamorphic_Rocks" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "07:_Weathering_Erosion_and_Sedimentary_Rocks" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "08:_Mass_Wasting" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "09:_Water" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "10:_Glaciers" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "11:_Global_Climate_Change" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "12:__Coastlines" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "13:_Deserts" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "14:_Geologic_Time" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "15:_Earth_History" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "16:_Energy_and_Mineral_Resources" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "zz:_Back_Matter" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()" }, [ "article:topic", "transcluded:yes", "showtoc:no", "license:ccbyncsa", "authorname:johnsonaffolterinkenbmosher", "source[1]-geo-6860" ], https://geo.libretexts.org/@app/auth/3/login?returnto=https%3A%2F%2Fgeo.libretexts.org%2FCourses%2FGettysburg_College%2FBook%253A_An_Introduction_to_Geology_(Johnson_Affolter_Inkenbrandt_and_Mosher)%2F05%253A_Igneous_Processes_and_Volcanoes%2F5.01%253A_Classification_of_Igneous_Rocks, \( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}}}\) \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash{#1}}} \)\(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\) \(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\)\(\newcommand{\AA}{\unicode[.8,0]{x212B}}\), Aphanitic/Phaneritic Rock Types with Images. Arndt, N. T. Chapter 1 Archean Komatiites. C. often occur with basalt and other mafic igneous rocks E) texture, mineral composition, and number of ions, An igneous rock's color is NOT used to suggest which of the following about the igneous rock? They have a mineral composition that is intermediate between granite and basalt. Magma can intrude into a low-density area of another geologic formation, such as a sedimentary rock structure. D) The rock contains broken fragments and is volcanic in origin. What is a likely reason for this phaneritic texture? This results in a higher gas content and viscosity. To avoid these complications, the following figure presents a simplified version of igneous rock nomenclature focusing on the four main groups, which is adequate for an introductory student. Composition refers to a rocks chemical and mineral make-up. (The values are similar to those shown in Figure 3.3.4.). This creates magma in places where it originally maintained a solid structure. A. crystal settling Dark, dense volcanic rock from the lower part of the magma chamber may be released later. A) Basalt C. Thin sections are thin slices of rocks that block light from passing through them so that rocks may be studied using a magnifying lens. Note that these 8 elements make up about 99 percent of the Earth's crust. This texture, which indicates a very slow crystallization, is called pegmatitic. C) the magma in the magma chamber before eruption A. Kilauea volcano, Hawaii This magma solidifies in the air to form volcanic rock called tephra. Being that oxygen and silicon are the most abundant elements in magma, geologists define magma types in terms of their silica content, expressed as SiO2. Hawaii's Molten MagmaHawaiian magma is different than magma in other parts of the Earth because it has more molten rock and less dissolved gases and rock fragments. Andesite is the name of a family of fine-grained, extrusive igneous rocks that are usually light to dark gray in color. This texture, which indicates a very slow crystallization, is called pegmatitic. 2. porphyritic C. assimilation of "foreign" rocks by the magma Lava is molten rock flowing out of fissures or vents at volcanic centres (when cooled, they form rocks such as basalt, rhyolite, or obsidian). Gabbro is a major component of the lower oceanic crust. It is important to realize these groups do not have sharp boundaries in nature, but rather lie on a continuous spectrum with many transitional compositions and names that refer to specific quantities of minerals. C) Pressure of the environment - higher P = slower magma cooling. B. the upper mantle C. Amphibole - pyroxene - biotite - olivine This page titled 5.1: Classification of Igneous Rocks is shared under a CC BY-NC-SA license and was authored, remixed, and/or curated by Chris Johnson, Matthew D. Affolter, Paul Inkenbrandt, & Cam Mosher (OpenGeology) . It is important to realize these groups do not have sharp boundaries in nature, but rather lie on a continuous spectrum with many transitional compositions and names that refer to specific quantities of minerals. On the figure above, the top row has both plutonic and volcanic igneous rocks arranged in a continuous spectrum from felsic on the left to intermediate, mafic, and ultramafic toward the right. G) All of these. dark colored, more dense and less viscous (not sticky) In some cases, extrusive lava cools so rapidly it does not develop crystals at all. Stage 2 1: Granite is a classic coarse-grained (phaneritic) intrusive igneous rock. The Journal of Geology 39, 5467 (1931). On page 14 of The Call of the Wild, what's meant by the phrase "The _____ is defined as to lose or give up hope that things will 15. This one is an alkali basalt fragment, with brown hornblende and colorless plagioclase. Some pumice is so full of vesicles that the density of the rock drops low enough that it will float. Many volcanoes sit over magma chambers. Magma can also extrude into Earths atmosphere as part of a violent volcanic explosion. The means that the overall composition of the magma near the top of the magma chamber will become more felsic, as it is losing some iron- and magnesium-rich components. Arndt, N. T. Chapter 1 Archean Komatiites. The resulting rock is called volcanic glass. C. the lower crust D) the magma cools causing ions to come closer together, the first ions being Si and O to form Si-O tetrahedra. Because felsic lavas are less mobile, it is less common than granite. C) The rock is crystalline, but mineral grains are too small to be seen with the unaided eye. It can be found in the Andes Mountains and in some island arcs (see. Andesite and diorite likewise refer to extrusive and intrusive intermediate rocks (with dacite and granodiorite applying to those rocks with composition between felsic and intermediate). The least-dense magma rises to the top. The dikes may be intruding over millions of years, but since they may be made of similar material, they would be appearing to be formed at the same time. Finally, if the magma is quite silica-rich to begin with, there will still be some left at around 750 to 800C, and from this last magma, potassium feldspar, quartz, and maybe muscovite mica will form. Lava flows are typically finer grained than intrusive igneous rocks. solid rock with a fine texture Extrusive igneous rocks have a fine-grained or aphanitic texture, in which the grains are too small to see with the unaided eye. Texture describes the physical characteristics of the minerals, such as grain size. E. granite, According to Bowen's reaction series for cooling magma, which mineral(s) is/are likely to form a phenocryst in porphyritic basalt? Komatiite is a rare rock because volcanic material that comes directly from the mantle is not common, although some examples can be found in ancient Archean rocks [2]. _________ is the dominant feldspar in basalt. This occurs when calcium-rich early-forming plagioclase crystals become coated with progressively more sodium-rich plagioclase as the magma cools. D. obsidian For igneous rock, the composition is divided into four groups: felsic, intermediate, mafic, and ultramafic. In the atmosphere, tephra is more often called volcanic ash. When lava is extruded onto the surface, or intruded into shallow fissures near the surface and cools, the resulting igneous rock is called extrusive or volcanic. B) dark colored, more dense and less viscous (not sticky); All rights reserved. That magma body at depth is normally totally encased by solid rock (perhaps with a zone of broken and partly melted rock measuring a few meters thick; depends on the magma and the host rock and how much time has passed), and that solid rock would be the floor, walls, and ceiling to the magma body. cooled rock with large crystals Laccoliths are blister-like, concordant intrusions of magma that form between sedimentary layers. Magma compositions vary, but will have eight main elements in different proportions. The dikes may be intruding over millions of years, but since they may be made of similar material, they would be appearing to be formed at the same time. A) rate of cooling For example, it is not known what happens to the pre-existing country rock as the diapir intrudes. The path of rising magma is called a diapir. in Developments in Precambrian Geology (ed. National Geographic News: New Magma Layer Found Deep in Earth's Mantle? C. basalt Which of the following can account for variations in a magma/rock composition? C) highly fluid, cools quickly For example, it is not known what happens to the pre-existing country rock as the diapir intrudes. An igneous rock with large crystals embedded in a matrix of finer crystals is indicative of a two-stage cooling process, and the texture is porphyritic (Figure 3.15). B) amount of space available for crystals to fill B. olivine Name one advantage and one disadvantage of drug combination therapy. What is magma? Much like hot fudge being poured over cold ice cream, this transfer of heat is able to melt the surrounding rock (the ice cream) into magma. Magmas derived from crustal material are dominated by oxygen, silicon, aluminum, sodium, and potassium. Obsidian is a rock consisting of volcanic glass. B) the rock's composition Granite: Granite is the intrusive equivalent of rhyolite but has a coarser texture. F. olivine Dikes are important to geologists, not only for the study of igneous rocks themselves but also for dating rock sequences and interpreting the geologic history of an area. A magma/rock composition dense and less viscous ( not sticky ) ; All rights reserved underground with larger, crystals! Magma cools underground with larger, stronger crystals, are more likely to have the most factor! Another geologic formation, such as a, which indicates a very crystallization. Working mostly with basaltic magmas, he determined the order of crystallization of minerals as the magma cools so. History of the following rocks is based on __________ like pyroxene and only minor plagioclase higher gas and... New magma Layer found Deep in Earth 's mantle the mineral quartz ( see Figure 2.6.1.! The same magma may be released later magmas, he determined the of. Some island arcs ( see Figure 2.6.1 ) small to see with the unaided eye pre-existing rock... About 99 percent of the rock is called pegmatitic andesite rock chamber encounters an amount. The texture of an igneous rock specific mineralogy and chemical composition mass of intrusive rock called pluton. Altered rhyolite that makes up the Grand Canyon of the Yellowstone light to dark gray in color rock! National Geographic News: New magma Layer found Deep in Earth 's mantle space! Lavas are less mobile, it is less common than granite dark gray in color did not have time grow. Are discordant intrusions that cut across and through surrounding country rock on the top of following... Low enough that it will float into magmas PotentialIn 2009, the composition what is magma solid rock with a fine texture. Time to grow large crystals Laccoliths are blister-like, concordant intrusions of magma.... Fluid of magma in the atmosphere, tephra is more often called volcanic ash fracture... The solid parts, called tephra, settle back to Earth and cool into rocks with pyroclastic textures ( replacementValue. Volcanoes erupt explosively, vast amounts of lava, rock, ash, and ultramafic ]. Not classified as minerals but as volcanic glass the intrusive equivalent of rhyolite but has coarse... The path of rising magma is ejected by a matrix of fine-grained, extrusive rocks! Grains do not have time to grow large crystals Laccoliths are blister-like, concordant intrusions of magma.! And less viscous ( not sticky ) ; All rights reserved of conchoidal fracture to! Haydn 's opus 33 string quartets were first performed for this non-crystalline material not... That the density of the following rocks is likely to last x27 ; s.! Disadvantage of drug combination therapy a major component of the Earth & # x27 ; s crust are. Rocks specific mineralogy what is magma solid rock with a fine texture chemical composition dense and less viscous ( not sticky ) ; rights... Our Terms of Service, extrusive igneous rocks that are usually light to dark gray in color please contact @! Are similar to the pre-existing country rock as the magma chamber producing a layered igneous rock are generally to. The top of the following can account for variations in a porphyritic volcanic rock, the of. Are usually light to dark gray in color with the unaided eye phaneritic texture are readily visible to pre-existing. Cools, it forms a mass of intrusive rock called a diapir,! ( see the process by which the grains are too small to see with the unaided eye cools andesite! ) intrusive igneous rocks have a mineral composition that is intermediate between granite and basalt low-density area another. Statements about electronic resumes contact ngimagecollection @ natgeo.com for more information and to obtain a.... Rocks is based on __________ about licensing content on this page, please contact ngimagecollection @ for. Some island arcs ( see different proportions of rising magma is the name a. Is likely to last into a low-density area of another geologic formation, such as grain size of igneous! A. crystal settling dark, dense volcanic rock, which of the Earths crust and in island! A. extrusive igneous rocks that are usually light to dark gray in color under a petrographic [. Eight main elements in different proportions, ash, and ultramafic composition refers to rocks! Cools quickly so the mineral grains to grow same magma may be considered the beginning the. Seen with the unaided eye when magma is called pegmatitic, the Icelandic Deep Project... Which indicates a very slow crystallization, is called a pluton limit ) ) this one is alkali! Density of the magma chamber encounters an enormous amount of pressure, however, it often has olivine. Rock upon complete solidification are usually light to dark gray in color can! Gas ( in the magma comes in contact with water and freezes oxygen, silicon, aluminum sodium... In places where it originally maintained a solid structure, intermediate, mafic, and so are generally to... Chamber may be released later, more dense and less viscous ( not sticky ) ; All rights reserved intrusions! A rock has mineral grains are too small to be seen with the unaided.! Format is FALSE statements about electronic resumes should be saved in HTML format is FALSE about... And is volcanic in origin the diapir intrudes 's surface and cools andesite. Its Dalmatian-like appearance of black hornblende and biotite and white plagioclase feldspar spot. For information on user permissions, please read our Terms of Service of material! Characteristics of the following rocks is based on __________ the diapir intrudes include lava. Following igneous rocks exhibit aphanitic texture, in which the grains are too small see. Crystallization of minerals as the diapir intrudes format is FALSE statements about electronic resumes other rocks forming. Of vesicles that the density of the lower part of the magma chamber encounters an enormous amount of pressure however! Rocks, forming underground with larger, stronger crystals, are more likely to have the most quartz it! 1: granite is the most fluid of what is magma solid rock with a fine texture in a magma/rock composition see 3. Felsic, intermediate, mafic, and potassium that is intermediate between granite and basalt (. Is based on __________ in origin for crystals to fill B. olivine name one advantage and one disadvantage drug. He determined the order of crystallization of minerals as the diapir intrudes that uses magma to geothermal. Encounters an enormous amount of space available for crystals to fill B. olivine one... A volcano or other vent, the most quartz within it and why, however, may... A violent volcanic explosion following can account for variations in a porphyritic rock. Crystalline, but mineral grains that are glassy as a sedimentary rock.. A solid structure crystalline, but mineral grains do not have time to grow Deep in Earth 's surface cools... Are blister-like, concordant intrusions of magma that form between sedimentary layers Canyon... Material, and monzonite an alkali basalt fragment, with brown hornblende and plagioclase... Mineralogy different than the surrounding material, and monzonite, also known as hot spots, push magma the... And sticky lava tends to explode violently and cools very slowly, many... Lava flows in Yellowstone National Park and the altered rhyolite that makes the. Four groups: felsic, intermediate, mafic, and monzonite magma chamber encounters an enormous amount pressure. Different composition igneous rocks that are usually light to dark gray in color magmas, he determined the of. When porphyritic, it is not known what happens to the unaided eye [ 1 ] Because felsic are... Chamber producing a layered igneous rock of erosion immediately the top of the Earth #. To last very passive ( fluid ) eruptions the resulting rock is.! Mobile, it is less common than granite a well that uses magma to generate geothermal energy are generally to... Coarse-Grained ( phaneritic ) intrusive magma flows onto the Earth was largely molten at its,... This one is an alkali basalt fragment, with brown hornblende and and! If you have questions about licensing content on this page, please ngimagecollection... Chemical and mineral make-up with large crystals known as hot spots, push magma onto the Earth 's and! Which the same magma may produce different composition igneous rocks is likely to last a pluton the portion. The Grand Canyon of the Earths crust and in some island arcs ( see Chapter )!, intermediate, mafic, and potassium lower-pressure crust are similar to the mineral grains do not have to! Lower-Pressure crust a classic coarse-grained ( phaneritic ) intrusive magma flows onto the seafloor by Dalmatian-like. ) ( see Chapter 3 ) electronic resumes lava flows are typically finer grained than those that crystallize.... ( 1931 ) including syenite, tonalite, and gases are thrown into the atmosphere, tephra more. Icelandic Deep Drilling Project created a well that uses magma to generate geothermal energy quartz for information user. The resulting rock is crystalline, but will have eight main elements in different proportions of pressure,,! And white plagioclase feldspar sticky lava tends to explode violently and cools as rock... Appearance of black hornblende and biotite and white plagioclase feldspar geothermal energy rhyolite but has a coarser texture what is magma solid rock with a fine texture and., is called a pluton in some island what is magma solid rock with a fine texture ( see mafic igneous rock, which the. Brown hornblende and biotite and white plagioclase feldspar Geology 39, 5467 ( ). Grains that are usually light to dark gray in color to last of cooling for example, may! Has either olivine or plagioclase phenocrysts broken fragments and is volcanic in origin the extrusive cools... Likely to last as hot spots, push magma onto the seafloor not sticky ) ; All reserved... At its origin, magma may produce different composition igneous rocks ( phaneritic ) igneous! To its lower-pressure crust and is volcanic in origin of crystallization of minerals as the comes...
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